10 



OTHER PARASITES WHICH ARE LIABLE TO BE 

 CONFUSED WITH WORMS. 



When searching, l)y dissection or otherwise, for parasitic 

 worms, it is not improbable that various other parasites of more or 

 less worm -like appearance will be found. 



The importance of collecting every tliintj of this kind, especially 



if there is any question 

 as to its identity, can- 

 not be too strongly 

 emphasised. Hence a 

 brief reference is made 

 here to some of the 

 parasitic creatures 

 which bear some re- 

 semblance to worms. 



Certain parasitic 

 Arthropods, in which 

 the limbs are degraded 

 or entirely lost, re- 

 semble worms in 

 general appearance 

 and are commonly 

 confused with them. 

 Among these may be 

 mentioned the insect 

 larv^ or maggots, 

 which make their way 

 into the mouth, nostrils 

 or stomach, or under 

 the skin of Mammals, 

 including Man. These 

 are the larval stages of 

 certain Flies, and most 

 of them attack Ungulates — (Horses, Cattle, &c.). Some, like the 

 "Warble " flies, raise tumours of considerable size under the skin, 

 in which the larvaB live and feed, and from which they eventually 

 emerge. The so-called " Screw-worm " similarly attacks Man. 

 In other cases, like the Gastrophilas of the Horse, the eggs 

 swallowed by the animal hatch in its stomach, and the larvas 

 thereupon attach themselves as true internal parasites to the 

 stomach-wall. They are true maggots and have the usual shape 

 of such creatures, tapering in front and broadened behind, and 

 armed with various rings of spines encircling the body. 



FIGCRE 12. 



A large Pentastomid, Pentastomii puli/zonnm, found in 



the Puff-adder ; natural size. [PENTA8TOMIDA.] 



